Fort Uncompahgre was constructed in 1828 by Antoine Robidoux, a trader based out of Mexican Santa Fé. The trading post was situated about two miles down from the confluence of the Gunnison and Uncompahgre Rivers near the present-day community of Delta in western Colorado. The precise location of the fort has been lost due to the shifting bed of the Gunnison River, but Robidoux chose the area because it afforded abundant timber for construction and firewood as well as pasture for pack animals. It was also a favored gathering spot of the Ute Indians and a natural ford nearby offered an easy river crossing.

The Utes apparently encouraged the presence of a trader in their territory so they could obtain firearms. Although Spanish law and, later, Mexican law prohibited the sale or trade of firearms to Indians, such activities might be conducted at a remote, rugged location without much fear of official sanction.

Robidoux established several trails for supplying Fort Uncompahgre. The first of these, known as the Mountain Branch of the Old Spanish Trail, led north out of Santa Fé, up into the San Luis Valley, northwest across Cochetopa Pass, then down into the Gunnison valley to the fort. This was a challenging route, but if not snowbound, it was much shorter than following the main branch of the Old Spanish Trail. The second trail, known as Robidoux’s Cutoff, was used for goods imported from St. Louis. The cutoff left the Santa Fé Trail near Bent’s Fort, proceeded westward to the vicinity of present-day Pueblo, then around the south end of the Wet Mountains and over Mosca Pass into the San Luis Valley. Here it joined with the Mountain Branch. The cutoff was advantageous because it was far shorter than freighting the goods north from Santa Fé and avoided Mexican customs, where taxes reached as high as 30 percent.

Little is known about the construction or layout of Fort Uncompahgre except that it was on the south bank of the Gunnison River. Few travelers passed through the fort because of its remote location. There are no known contemporary descriptions of the fort, but it probably resembled Fort Uintah, another fort Robidoux built in present-day eastern Utah. Fort Uncompahgre probably consisted of a few crude log buildings surrounded by a fence of cottonwood pickets. This type of construction would have been acceptable to the Utes, who were sensitive about permanent structures built on their lands.

Accounts indicate that the fort had between fifteen and eighteen male employees. These men would have been responsible for trading, limited trapping, preparing hides and skins, and bundling fur packs. Additionally, the cottonwood pickets and log structures would have needed continual maintenance and replacement as the soft cottonwood rotted. Transportation to the area was difficult and expensive, and anything that could be made or grown locally would reduce costs significantly. Employees probably raised a garden, which may have included corn, wheat, beans, lentils, potatoes, melons, and squash. Sheep or goats were probably also kept at the fort.

Robidoux’s employees were all Mexicans, probably from the Santa Fé area. Employees typically worked under a one-year contract and would be paid in trade goods received at the end of their service. At the time, Nuevo México (as the northern colonies of Old Mexico were known) had a surplus of labor and wage rates were approximately $5 per month for skilled craftsmen, while unskilled labor was worth no more than $2 per month.

The primary structure on the post would have been the trade room, where trappers and Indians would have brought their skins and furs to be graded and weighed. They could then choose from a selection of trade goods displayed in another area of the trade room. The living quarters of the trader or his principal would have adjoined the trade room. Other structures on the post probably included a storage building for the furs, a kitchen/living quarters for the post cook, and a blacksmith/carpenter’s shop.

In September 1831, authorities in Santa Fé granted Robidoux a license for a second trading post near the confluence of the Whiterock and Uintah rivers. This post, known as Fort Uintah, served both Anglo and Mexican trappers as well as Ute and sometimes Shoshoni Indians. Rufus Sage, in Rocky Mountain Life, described this fort from his visit in the early 1840s as follows: “Robideau’s Fort is situated on the right bank of the Uintah . . . The trade of this post is conducted principally with the trapping parties frequenting the Big Bear, Green, Grand, and the Colorado Rivers, with their numerous tributaries, in search of fur-bearing game. A small business is also carried on with the Snake and Utah Indians, living in the neighborhood of this establishment. The common articles of dealing are horses, with beaver, otter, deer, sheep, and elk skins, in barter for ammunition, fire-arms, knives, tobacco, beads, awls, &c.”

By 1837, the Hudson’s Bay Company was becoming competitive in the area, and to hold them back, Robidoux built a third post—Fort Robidoux—near the confluence of the Green and White rivers in present-day Utah. Fort Robidoux was probably just a temporary post, and in 1838, when the Hudson’s Bay Company withdrew from the Uintah Basin, it was abandoned.

Toward the end of the 1830s, the price of beaver pelts declined precipitously. To make up for lost revenues, Fort Uncompahgre increased its trade in California horses and Indian slaves. Although Spanish and, later, Mexican authorities prohibited the taking of new slaves, the prohibition was not enforced. Powerful tribes would capture women and children of their weaker neighbors and sell them in the northern colonies (New Mexico), where demand was high for laborers and wives. In the 1830s, boys between the ages of eight and twelve years were valued at $50 to $100 in trade goods, and girls were worth approximately twice as much.

By 1841, other developments were changing the economics of the fur trade. The Oregon Trail had opened up, taking a steady stream of emigrants across the plains to Oregon and California. In addition to emigrants, the trail became a major route for hauling freight that supplied posts such as Fort Hall and Fort Bridger. The resulting lower freight costs, combined with industrial expansion in the East, meant the prices for trade goods were much lower than what Robidoux could offer with his Santa Fé–based operations. The Indians concluded that the Santa Fé and Taos traders, including Robidoux, had cheated them for years.

During summer 1843, hostilities broke out between Utes and Mexicans in the Santa Fé area. Warfare spread up the San Luis Valley and into the Gunnison Basin, engulfing Fort Uncompahgre.

Although it was known as a fort, Robidoux’s structure was designed more as a holding area for livestock and to secure trade goods and furs; it was never intended as a defensive structure during war. With one exception, all of the Mexicans were slaughtered and their women taken prisoner. Only a single Mexican trapper, Calario Cortez, escaped the carnage. He arrived in Taos fourteen days later, hungry and exhausted.

The Utes also captured an American visiting the fort. He was later released with a message for Robidoux telling him that the furs, hides, and buildings were intact, and that the Utes’ quarrel was with the Mexicans, not the Americans or the French. The Utes’ motivation for leaving the fort unscathed is uncertain. Did they expect that Robidoux would return to the fort as if nothing had happened, or were they trying to lure him back so he too could be killed? It is also not known why the Utes did not attack Fort Uintah, which was also staffed by Mexicans.

Fort Uncompahgre was left vacant for about two years before local Utes destroyed it. Robidoux never returned to the Uintah Basin to trap or trade for furs.

In 1990 Fort Uncompahgre was reconstructed upriver from its presumed original location, on land owned by the city of Delta. There has been renewed interest in the fort in recent years, and in 2015 the reconstructed fort was reopened to the public.

Adapted from the Old Spanish Trail Association, “Fort Uncompahgre,” n.d.